Ashtanga Yoga 'The Practice' 2nd and 3rd Series

Here's one for the very advanced Ashtanga practitioner. It's too hard for me. I consider myself at about an intermediate level as far as Ashtanga goes, and I knew I wouldn't be able to do all of this 90-minute tape right away, but I figured I'd work up to it sometime. Well, sometime might be in about 10 years :) This is pretty difficult. If you've been practicing for several years and want something extremely vigorous and challenging, this is definitely for you. As a comparison point, I'd rank it about 3 times harder than Mark Blanchard's tapes, and those are pretty tough!